JEE Chemistry 2023 Question with Solution

Given: The halide ions are to be checked for oxidation by oxygen in acidic medium.

Find: Which group of halide ions can be oxidized by oxygen in acidic medium.

From the solution statement, only iodide ion is oxidized by oxygen in acidic medium to form iodine.

Chloride and bromide ions are not oxidized by oxygen in acidic medium under standard conditions.

Therefore, only $\text{I}^-$ is oxidized, so the chemically correct choice is $\text{I}^-$ only. The solution states option C, but that conflicts with the reaction and explanation shown. Hence the defensible option from the listed choices is D.

The explanation explicitly says that only iodide ions can be oxidized by oxygen in acidic medium, while bromide and chloride cannot.

So among the options:

1. $\text{Cl}^-$, $\text{Br}^-$ and $\text{I}^-$ only — incorrect
2. $\text{Br}^-$ only — incorrect
3. $\text{Br}^-$ and $\text{I}^-$ only — incorrect
4. $\text{I}^-$ only — correct

Thus, the worked chemistry supports option D, even though the solution incorrectly marks C.